MC_StepBlockDetection_BkPlcMc

The function block is used for referencing via a limit switch. The function block outputs the position of the cam to the outside via RecordedPosition. No position is set.

Inputs

VAR_INPUT
    Execute:                 BOOL; 
    Direction:               MC_Direction_BkPlcMc; 
    Velocity:                LREAL; 
    Acceleration:            LREAL; 
    Deceleration:            LREAL; 
    Jerk:                    LREAL; 
    SetPosition:             LREAL; 
    DetectionVelocityLimit:  LREAL; 
    DetectionVelocityTime:   LREAL; 
    TorqueLimit:             LREAL; 
    TorqueTolerance:         LREAL; 
    TimeLimit:               TIME; 
    DistanceLimit:           LREAL; 
    BufferMode:              MC_BufferMode_BkPlcMc:=Aborting_BkPlcMc; 
END_VAR

Name	Type	Description
Execute	BOOL	The homing is initiated by a rising edge at this input.
Direction	MC_Direction_BkPlcMc	A direction preset coded according to MC_Direction_BkPlcMc.
Velocity	LREAL	[mm/s] The required motion velocity in actual value units of the axis per second.
Acceleration	LREAL	[mm/s²] The required acceleration in actual value units of the axis per square second. If this parameter is 0.0, it is replaced by a default value from the axis parameters.
Deceleration	LREAL	[mm/s²] The required deceleration in actual value units of the axis per square second. If this parameter is 0.0, it is replaced by a default value from the axis parameters.
Jerk	LREAL	[mm/s³] The required jerk in actual value units of the axis per square second. If this parameter is 0.0, it is replaced by a default value from the axis parameters.
SetPosition	LREAL	Required position on the referencing cam.
DetectionVelocityLimit	LREAL	[mm/s] Velocity limit to reliably detect a stop
DetectionVelocityTime	LREAL	[s] Time in which the actual velocity must be below the DetectionVelocityLimit in order to reliably detect the fixed stop.
TorqueLimit	LREAL	[Bar] Limitation for the pressure
TorqueTolerance	LREAL	[Bar] Tolerance for the pressure
TimeLimit	TIME	After this time, the referencing is canceled with error. At zero, time monitoring is disabled.
DistanceLimit	LREAL	After this distance, the referencing will be aborted with an error. At zero, the distance monitoring is disabled.
BufferMode	MC_BufferMode_BkPlcMc

Inputs/outputs

VAR_INOUT
    Axis:               Axis_Ref_BkPlcMc;
END_VAR

Name	Type	Description
Axis	Axis_Ref_BkPlcMc	Here, the address of a variable of type Axis_Ref_BkPlcMc should be transferred.

Outputs

VAR_OUTPUT
    Done:               BOOL;
    Busy:               BOOL;
    Active:             BOOL;
    CommandAborted:     BOOL;
    Error:              BOOL;
    ErrorID:            UDINT;
    RecordedPosition:   LREAL;
END_VAR

Name	Type	Description
Done	BOOL	Successful processing is indicated here
Busy	BOOL	Indicates that a command is being processed.
Active	BOOL	Readiness for operation is indicated here.
CommandAborted	BOOL	Here an abort of the command is indicated.
Error	BOOL	The occurrence of an error is indicated here.
ErrorID	UDINT	An encoded error message is provided here.
RecordedPosition	LREAL	[mm] Determined position of the referencing cam.

Behavior of the function block

On a rising edge at Execute the function block checks the transferred axis interface. A number of problems can be detected and reported during this process:

At Direction, MC_Positive_Direction_BkPlcMc, MC_Negative_Direction_BkPlcMc, is accepted
The DistanceLimit must have a value greater than the increment resolution.

The parameters Velocity, Acceleration, Deceleration and Jerk are transferred to MC_MoveVelocity_BkPlcMc. After the cam has been detected, the position is communicated via RecordedPosition and a MC_Halt_BkPlcMc stops the movement.

A hard stop is detected when the actual velocity for the time DetectionVelocityTime is below DetectionVelocityLimit or the current pressure is greater than TorqueLimit minus TorqueTolerance. If no fixed stop is detected within DistanceLimit or TimeLimit, referencing is aborted with an error.

During processing, the function block reports Busy and Active. After successful processing Done is reported back. If a subordinate function block reports an error, this is reported via Error and ErrorID.